The modern medicine from the last 25 years developed a lot in terms of assisted reproduction. The therapeutic methods in the infertility treatments lead to a success rate of up to 35-45% for each pregnancy obtained through the in vitro fertilization, according to the patient’s age and health.

Cumulative, this percentage increase with up to 70-80% after three cycles of therapy. Considering the conception rate of a fertile couple which is between 15-20% in every month of their life, it is obvious that the in vitro fertilization offers big success rates.

The success rate of an in vitro fertilization is influenced of many factors including the embryo development, the mother’s age, sperm’s quality and even the patients selected. But usually the success rate of a pregnancy obtained through in vitro fertilization is similar to the probability to conceive a baby in a natural way: 37% if the woman is under 35 and 28% for women between 36 and 39 years old.

The success rate is average 13% for women over 40 years and after 45 years the probability for a pregnancy decrease considerably. The rate of spontaneous miscarriage in the in vitro fertilization is the same as for natural pregnancies. There are registered entopic pregnancies in 3-5% cases of pregnancy obtained through in vitro fertilization.

An Israeli study at which participated 219 women who resorted to in vitro fertilization shows that the chances are higher for the patients who were amused by a “professional medical clown” immediately after the embryo was transferred to their uterus. Another Brazilian study shows that the success rate of in vitro fertilizations is higher during spring time.

The reason for the differences in efficiency isn’t clear. Specialists estimate that once spring is coming the increased quantity of light simulates the brain to synthesize the hormones which regulate the secretion of gonadotropic. Thus the ovary will product more estradiol with role in fecundation and than in the embryo’s development.